1. Field of the Invention
The present invention concerns an exhaust nozzle assembly, in particular for a turbojet engine and provides a unique control system for adjusting the position of a plurality of nozzle flap assemblies.
2. Brief Description of the Prior Art
U.S. Pat. No. 4,466,573 describes an exhaust nozzle assembly for a turbojet engine wherein a plurality of first or "hot" flaps are pivotally attached at their upstream edges to an exhaust outlet pipe of the engine. A plurality of control cylinders, the bodies of which are connected to stationary parts of the nozzle, are connected to the first flaps by a transmission lever assembly. The number of first flaps is twice the number of the transmission levers, and each lever extends essentially over the entire width of alternate first flaps. These control levers are pivotally attached to an annular structural element affixed to the outlet pipe. The control rods of the control cylinders are pivotally attached to at least one of each two control levers at points spaced apart from the pivoting axes of the control levers.
In this known nozzle flap system, the pivoting movements of each pair of control levers are synchronized by two systems of parallel levers, each comprising an elbow lever interconnected at their pivot points by a torsion tube. One end of each elbow lever is attached to the annular structural element, while the other end is connected by a rectilinear lever to the upstream edge of the corresponding control lever. The mechanical system which ensures synchronization of the pivoting motions of the two adjacent control levers of the known nozzle system is relatively complex, heavy and expensive. This configuration also is extremely complicated since it must carry a large number of interconnecting levers, some of which serve to articulate the annular element to the upstream end of the exhaust pipe while others interconnect the same annular element with the flaps, the transmission levers, the bodies of the control cylinders and the synchronzing lever system.